package com.changgou.system.filter;

import com.changgou.system.util.JwtUtil;
import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class AuthorizeFilter implements GlobalFilter,Ordered {

    private static final String AUTHORIZE_TOKEN = "token";
    
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1.获取请求
        ServerHttpRequest request = exchange.getRequest();
        //2.获取响应
        ServerHttpResponse response = exchange.getResponse();
        //3.如果是登录则 放行
        if(request.getURI().getPath().contains( "/admin/login" )){
            return chain.filter( exchange );
        }
        //4.获取请求头
        HttpHeaders headers = request.getHeaders();
        //5.请求头中获取令牌
        String token = headers.getFirst( AUTHORIZE_TOKEN );
        //6.判断请求头是否有令牌
        if (StringUtils.isEmpty(token)){
            //7.没有，响应中放入返回的状态码，没有访问权限，返回
            response.setStatusCode( HttpStatus.UNAUTHORIZED );
            response.setComplete();
        }
        //8.有，则解析令牌
        try {
            JwtUtil.parseJWT( token );
        } catch (Exception e) {
            e.printStackTrace();
            //9.解析jwt令牌出错，说明令牌过期或者为伪造等不合法情况出现，返回
            response.setStatusCode( HttpStatus.UNAUTHORIZED );
            response.setComplete();
        }
        //10.放行
        return chain.filter( exchange );
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
